A plea seeking the release of adequate quantity of water in Ganga to maintain the minimum environment flow for sustaining wildlife and river ecology on Tuesday prompted the National Green Tribunal to seek the responses of the Centre and others.

E-flow defines the quantity, timing and quality of water flow required to sustain freshwater and estuarine ecosystems, besides human livelihood.

A bench headed by acting Chairperson Justice UD Salvi issued notices to the ministries of Environment and Forest, Ministry of Water Resources, Central Pollution Control Board, National Mission for Clean Ganga, Uttarakhand Jal Vidyut Nigam Ltd and others while seeking their replies before March 8.

The NGT was hearing a plea filed by environment activist Vikrant Tongad seeking directions to maintain a minimum environment flow in Ganga to maintain wildlife and river ecology, alleging that a “substantial flow” of the Ganga was being diverted in Dehradun to a side canal for a power plant.

“Direct Respondent no 2 (Water resources) and Respondent no 4 (NMCG) to release into the main stream of the Ganga a minimum environment flow at all times of ‘not less than 1/3rd the average virgin flow of the river in the wet period, but more than 40 per cent of the dry period’ as suggested by IIT consortium,” the plea said.

Tongad said that minimum e-flow was vital for maintaining wildlife and river ecology, sustaining religious sentiments and quality of life for downstream human populations, aquatic life and wildlife, as the Uttarakhand High Court has granted status of “living entity” to Ganga and Yamuna.

The plea, filed through advocates Ritwick Dutta and Rahul Choudhary, claimed that substantial flow of the river Ganga was being diverted at Pashulok Barrage in Dehradun district to a side canal for a hydroelectric power plant of 144 Megawatt capacity.

“The diversion has led to sparse water flow in the main stream of Ganga downstream from the barrage flowing towards Haridwar and for majority of the year there is close to no water downstream of the Pashulok Barrage near Veerpur, Rishikesh,” it said.

The petition contended that the stretch of Ganga from the Pashulok Barrage till Motichur in Haridwar has become almost completely dry and was critically impacting the aquatic life, river ecology and human population present here who are dependent on the water for their needs.

The tribunal had earlier directed all states to maintain a minimum environmental flow of 15 to 20 per cent of the average lean season course in their rivers.